CN114828663A

CN114828663A - Formulations for aerosol-generating systems

Info

Publication number: CN114828663A
Application number: CN202080087485.6A
Authority: CN
Inventors: I·陶里诺
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2019-12-18
Filing date: 2020-12-16
Publication date: 2022-07-29
Also published as: WO2021122845A1; BR112022011449A2; KR20220116469A; US20230023830A1; JP2023507455A; EP4076025A1

Abstract

A formulation (211) for an aerosol-generating system, the formulation (211) comprising: one or more aerosol forming agents; one or more metal salts; and one or more polymeric thickeners. The formulation (211) has a polymeric thickener content of greater than or equal to about 0.5 wt%. The one or more metal salts include one or more metal stearates. An aerosol-generating article (200) for an aerosol-generating system, the aerosol-generating article (200) comprising the formulation (211). An aerosol-generating system, the aerosol-generating system comprising: the formulation (211); and a nebulizer (222) configured to generate an aerosol from the formulation (211).

Description

Formulations for aerosol-generating systems

Technical Field

The present invention relates to a formulation for an aerosol-generating system. The invention also relates to an aerosol-generating article comprising a formulation for an aerosol-generating system and to an aerosol-generating system comprising a formulation and a nebulizer.

Background

Aerosol-generating systems for delivering an aerosol to a user typically include a nebulizer configured to generate an inhalable aerosol from a formulation. Some known aerosol-generating systems include a thermal atomizer (such as an electric heater) configured to heat and vaporize a formulation to produce an aerosol. A typical formulation for an aerosol-generating system is a nicotine formulation, which may be a liquid nicotine formulation comprising an aerosol former such as glycerol and/or propylene glycol.

It would be desirable to provide a formulation which, when used in an aerosol-generating system, exhibits a reduced risk of leakage compared to typical formulations.

Disclosure of Invention

A formulation for an aerosol-generating system is provided. The formulation may comprise one or more aerosol-forming agents. The formulation may comprise one or more polymeric thickeners. The formulation can have a polymeric thickener content of greater than or equal to about 0.5 wt%.

There is also provided a formulation for an aerosol-generating system, the formulation comprising: one or more aerosol forming agents; and one or more polymeric thickeners, wherein the formulation has a polymeric thickener content of greater than or equal to about 0.5 wt%.

There is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a formulation comprising: one or more aerosol forming agents; and one or more polymeric thickeners, wherein the formulation has a polymeric thickener content of greater than or equal to about 0.5 wt%.

There is also provided an aerosol-generating device comprising: a formulation, the formulation comprising: one or more aerosol forming agents; and one or more polymeric thickeners, wherein the formulation has a polymeric thickener content of greater than or equal to about 0.5 wt%.

There is also provided an aerosol-generating system comprising: a formulation, the formulation comprising: one or more aerosol forming agents; and one or more polymeric thickeners, wherein the formulation has a polymeric thickener content of greater than or equal to about 0.5 wt%; and a nebulizer configured to generate an aerosol from the formulation.

As used herein, the term "aerosol-forming substrate" relates to a substrate that is capable of releasing volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate or by other means of atomization. The aerosol-forming substrate may be a liquid. The liquid may be an electronic liquid. The liquid may be a solution. The liquid may be a gel. Colloids can have discrete solid particles dispersed in a continuous liquid. The colloid may have discrete liquid particles dispersed in a continuous liquid. Colloids can have discrete liquid particles dispersed in a continuous solid.

Unless otherwise indicated, the weight percentages of the formulation components described herein are based on the total weight of the formulation.

Advantageously, the formulation provides a way to internally seal the reservoir of an aerosol-generating system containing the formulation by forming a barrier after each use of the aerosol-generating system. The formulation may initially be provided as a liquid in a reservoir of an aerosol-generating system. As with typical aerosol-generating systems, the formulation may be heated to form an aerosol. At least a portion of the formulation in the heater region may solidify to form a solid layer when the formulation cools after heating. The resulting solid layer may cover the entire opening of the reservoir. The solid layer may act as a barrier to seal the reservoir. Sealing the reservoir in this manner may advantageously reduce the risk of leakage of the formulation from the reservoir.

Sealing the reservoir in this way may advantageously prevent overflow of the aerosol-generating system due to leakage of the formulation from the reservoir between uses of the aerosol-generating system.

The solid layer may advantageously be melted or evaporated by a heater of the aerosol-generating system. The solid layer may then be transformed as the formulation cools or after the formulation has cooled between each use, thereby resealing the reservoir and again preventing the formulation from leaking from the reservoir. Evaporating the solid layer in this way may allow for reuse of the aerosol-generating system.

The one or more polymeric thickeners may be selected from the group consisting of: polyvinyl acetate (PVA), polyvinyl alcohol (PVOH), polyethylene glycol (PEG), polyglycolic acid (PGA), polylactic acid (PLA), Polydioxanone (PDO), Polycaprolactone (PCL), Polyethylene (PE), polypropylene glycol (PPG), and starch.

All starches are composed of amylose and amylopectin in different ratios. The selection of a particular starch for use in the formulation may be based on the ratio of amylose to amylopectin, depending on the desired functionality of the starch. The starch may be corn starch or wheat starch. Preferably, the starch is corn starch, preferably the starch is waxy corn starch. Waxy corn starch is essentially pure amylopectin with only traces of amylose. Waxy corn starch has been found to produce a better, more elastic barrier. It should be noted that the molecular weight of starch varies due to natural variation.

Preferably, when the polymeric thickener is polyethylene, the polyethylene is a low density polyethylene.

Preferably, the one or more polymeric thickeners are selected from the group consisting of: polyvinyl alcohol, polyethylene glycol, polypropylene glycol and starch.

More preferably, the one or more polymeric thickeners are selected from the group consisting of: polyvinyl alcohol, polyethylene glycol and polypropylene glycol.

Even more preferably, the one or more polymeric thickeners are selected from the group consisting of: polyvinyl alcohol and polyethylene glycol.

Most preferably, the one or more polymeric thickeners consist of polyvinyl alcohol.

The formulation can have a polymeric thickener content of greater than or equal to about 0.5 wt%. The formulation can have a polymeric thickener content of greater than or equal to about 1 wt%. The formulation can have a polymeric thickener content of greater than or equal to about 2 wt%. The formulation can have a polymeric thickener content of greater than or equal to about 5 wt%. The formulation can have a polymeric thickener content of greater than or equal to about 8 wt%. The formulation can have a polymeric thickener content of greater than or equal to about 10 wt%.

The formulation can have a polymeric thickener content of less than or equal to about 20 wt%. The formulation may have a polymeric thickener content of less than or equal to about 18 wt%. The formulation can have a polymeric thickener content of less than or equal to about 15 wt%. The formulation can have a polymeric thickener content of less than or equal to about 12 wt%. The formulation can have a polymeric thickener content of less than or equal to about 10 wt%. The formulation can have a polymeric thickener content of less than or equal to about 8 wt%. The formulation can have a polymeric thickener content of less than or equal to about 5 wt%. The formulation can have a polymeric thickener content of less than or equal to about 2 wt%. The formulation can have a polymeric thickener content of less than or equal to about 1 wt%.

The formulation may have a polymeric thickener content of between about 0.5 wt% and about 20 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 18 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 15 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 12 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 10 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 8 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 5 wt%. The formulation can have a polymeric thickener content of between about 0.5 wt% and about 2 wt%. The formulation may have a polymeric thickener content of between about 0.5 wt% and about 1 wt%.

The formulation may have a polymeric thickener content of between about 1% and about 20% by weight. The formulation may have a polymeric thickener content of between about 1% and about 18% by weight. The formulation may have a polymeric thickener content of between about 1% and about 15% by weight. The formulation may have a polymeric thickener content of between about 1% and about 12% by weight. The formulation may have a polymeric thickener content of between about 1% and about 10% by weight. The formulation may have a polymeric thickener content of between about 1% and about 8% by weight. The formulation may have a polymeric thickener content of between about 1% and about 5% by weight. The formulation may have a polymeric thickener content of between about 1% and about 2% by weight.

The formulation may have a polymeric thickener content of between about 5 wt% and about 20 wt%. The formulation can have a polymeric thickener content of between about 5 wt% and about 18 wt%. The formulation may have a polymeric thickener content of between about 5 wt% and about 15 wt%. The formulation may have a polymeric thickener content of between about 5 wt% and about 10 wt%. The formulation may have a polymeric thickener content of between about 5 wt% and about 12 wt%. The formulation may have a polymeric thickener content of between about 5 wt% and about 10 wt%. The formulation may have a polymeric thickener content of between about 5 wt% and about 8 wt%.

The one or more polymeric thickeners may be one or more polymers. The one or more polymers may be one or more synthetic polymers.

The one or more polymeric thickeners may have a weight average molecular weight (M) greater than or equal to 6000g/mol _w ). The one or more polymeric thickeners may have a weight average molecular weight greater than or equal to 60000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight greater than or equal to 100000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight greater than or equal to 140000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight greater than or equal to 200000 g/mol.

The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 8000000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 5000000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 2000000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 1000000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 500000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 200000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of less than or equal to 190000 g/mol.

The one or more polymeric thickeners may have a weight average molecular weight between 6000g/mol and 8000000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight between 60000g/mol and 500000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight between 100000g/mol and 200000 g/mol. The one or more polymeric thickeners may have a weight average molecular weight of between 140000g/mol and 190000 g/mol.

The formulation may comprise one or more metal salts.

The bonding between the one or more metal salts and the one or more aerosol-formers in the formulation may increase the boiling point of the one or more aerosol-formers. When the formulation comprises nicotine, this may advantageously enhance the efficiency of evaporation of nicotine from the formulation when used in an aerosol-generating system compared to a typical liquid nicotine formulation which does not comprise one or more metal salts.

The one or more metal salts may be selected from the group consisting of: metal alginates, metal benzoates, metal cinnamates, metal cycloheptane carboxylates, metal levulinates, metal propionates, metal stearates, and metal undecanoates.

Preferably, the one or more metal salts are selected from the group consisting of: metal cinnamates, metal cycloheptane carboxylates, metal levulinates, metal propionates, metal stearates, and metal undecanoates.

Preferably, the one or more metal salts are selected from the group consisting of: metal benzoates, metal cinnamates, metal cycloheptane carboxylates, metal levulinates, metal propionates, metal stearates, and metal undecanoates.

Preferably, the one or more metal salts are selected from the group consisting of: metal cinnamates, metal cycloheptane carboxylates, metal stearates, and metal undecanoates.

The one or more salts may be salts of any suitable metal.

Preferably, the one or more metal salts are alkali metal salts.

More preferably, the one or more metal salts are sodium salts.

Preferably, the evaporable barrier comprises one or more non-saccharide sodium salts. Preferably, the one or more metal salts comprise one or more non-saccharide sodium salts.

The one or more metal stearates can include sodium stearate.

Metal salts having a high molecular weight may improve the above-mentioned advantages relating to nicotine evaporation efficiency and solid layer formation rate. However, if the molecular weight of the metal salt is too high, properties such as solubility begin to be negatively affected. Advantageously, the inclusion of sodium stearate in the formulation may provide an optimum balance in terms of increasing the evaporation efficiency and rate of solid layer formation of nicotine while maintaining solubility.

More preferably, the one or more sodium salts are selected from the group consisting of: sodium benzoate, sodium cinnamate, sodium cycloheptanecarboxylate, sodium levulinate, sodium propionate, sodium stearate, and sodium undecanoate.

Preferably, the one or more metal salts are selected from the group consisting of: sodium cinnamate, sodium cycloheptanecarboxylate, sodium levulinate, sodium propionate, sodium stearate, and sodium undecanoate.

Preferably, the one or more sodium salts are selected from the group consisting of: sodium benzoate, sodium cinnamate, sodium cycloheptanecarboxylate, sodium levulinate, sodium propionate, sodium stearate, and sodium undecanoate.

Preferably, the one or more metal salts are selected from the group consisting of: sodium cinnamate, sodium cycloheptanecarboxylate, sodium stearate, and sodium undecanoate.

Most preferably, the one or more metal salts is sodium stearate.

Advantageously, the inclusion of one or more metal stearates in the formulation can increase the rate of formation of the solid layer. In one particular example, advantageously, a formulation comprising a combination of a metal stearate and glycerin produces a harder solid layer.

Advantageously, the covalent bonding between the one or more metal stearates and the one or more aerosol-forming agents in the formulation can further increase the boiling point of the one or more aerosol-forming agents. When the formulation comprises nicotine, this may advantageously enhance the efficiency of evaporation of nicotine from the formulation when used in an aerosol-generating system compared to a typical liquid nicotine formulation that does not comprise one or more metal stearates.

The formulation may have a metal salt content of greater than or equal to about 0.5 wt%. The formulation may have a metal salt content of greater than or equal to about 0.75 wt%. The formulation can have a metal salt content greater than or equal to about 1% by weight. The formulation can have a metal salt content greater than or equal to about 1.5 wt%. The formulation can have a metal salt content of greater than or equal to about 2 wt%.

The formulation may have a metal salt content of less than or equal to about 10 wt%. For example, the formulation may have a metal salt content of less than or equal to about 5 wt%. The formulation may have a metal salt content of less than or equal to about 2 wt%.

The formulation may have a metal salt content of between about 0.5 wt% and about 10 wt%. For example, the formulation may have a metal salt content between about 0.5 wt% and about 5 wt%. The formulation may have a metal salt content of between about 0.5 wt% and about 2 wt%.

The formulation may have a metal salt content between about 1% and about 10% by weight. For example, the formulation may have a metal salt content of between about 1% and about 5% by weight. The formulation may have a metal salt content of between about 1% and about 2% by weight.

The formulation can have an aerosol former content of greater than or equal to about 5% by weight. The formulation can have an aerosol former content of greater than or equal to about 10% by weight. The formulation can have an aerosol former content of greater than or equal to about 20% by weight. The formulation can have an aerosol former content of greater than or equal to about 30% by weight. The formulation can have an aerosol former content of greater than or equal to about 40% by weight.

The formulation can have an aerosol former content of greater than or equal to about 50% by weight.

The formulation can have an aerosol former content of greater than or equal to about 60% by weight. The formulation can have an aerosol former content of greater than or equal to about 70% by weight. The formulation can have an aerosol former content of greater than or equal to about 80% by weight. The formulation can have an aerosol former content of greater than or equal to about 90% by weight.

The formulation can have an aerosol former content of less than or equal to about 95% by weight.

The formulation may have an aerosol former content of between about 5% and about 95% by weight. For example, the formulation may have an aerosol former content of between about 10% and about 95% by weight. The formulation may have an aerosol former content of between about 20% and about 95% by weight. The formulation may have an aerosol former content of between about 30% and about 95% by weight. The formulation may have an aerosol former content of between about 40% and about 95% by weight.

Preferably, the formulation has an aerosol former content of between about 50% and about 95% by weight.

The formulation may have an aerosol former content of between about 60% and about 95% by weight. For example, the formulation may have an aerosol former content of between about 70% and about 95% by weight. The formulation may have an aerosol former content of between about 80% and about 95% by weight. The formulation may have an aerosol former content of between about 90% and about 95% by weight.

The formulation may comprise one or more aerosol-formers selected from the group consisting of: 1, 3-butylene glycol, glycerol, propylene glycol, triethylene glycol and sorbitol. The glycerol may comprise vegetable glycerol.

The one or more aerosol-forming agents may comprise a combination of glycerin and propylene glycol. The one or more aerosol-forming agents may comprise a combination of vegetable glycerin and propylene glycol.

In some preferred embodiments, the one or more aerosol-forming agents comprise a major amount of glycerin. It has been found that glycerol-based formulations can provide a harder solid material. It has also been found that the inclusion of a small amount of propylene glycol in a glycerin-based formulation can provide a less rigid or less brittle solid than a glycerin-based composition that does not contain propylene glycol.

As discussed below, the inclusion of propylene glycol in the formulation may improve evaporation of the formulation, which may result in more aerosol being produced for a given heating cycle.

By including propylene glycol in a nicotine-containing glycerol-based formulation, the nicotine content of the aerosol may also be improved due to more efficient evaporation of nicotine due to the lower boiling point (188 ℃) of propylene glycol compared to glycerol (290 ℃). However, if there is a large amount of propylene glycol in the formulation, the nicotine content of the aerosol will be reduced because the propylene glycol can evaporate during the heating cycle. Thus, it may be advantageous to have a limited amount of propylene glycol in the nicotine formulation.

The ratio of the weight percent of glycerin content to the weight percent of propylene glycol content in the formulation can be greater than or equal to about 1.

The ratio of the weight percent of glycerin content to the weight percent of propylene glycol content in the formulation can be greater than or equal to about 1.5. The ratio of the weight percent of glycerin content to the weight percent of propylene glycol content in the formulation can be greater than or equal to about 2. The ratio of the weight percent of glycerin content to the weight percent of propylene glycol content in the formulation can be greater than or equal to about 2.5. The ratio of the weight percent of glycerin content to the weight percent of propylene glycol content in the formulation can be greater than or equal to about 3.

It has been found that such compositions can provide a balance of hardness and rigidity or brittleness to provide an optimal seal in addition to the advantageous evaporation properties discussed herein.

The one or more aerosol-formers may include one or more polyols. The one or more polyols may include one or more water-miscible polyols. As used herein, the term "water-miscible polyol" describes a polyol that is a liquid at 20 ℃ and is mixed with water in any proportion to form a homogeneous solution.

The formulation may comprise water.

The formulation may have a water content of greater than or equal to about 0.5 wt%. The formulation can have a water content greater than or equal to about 1% by weight. The formulation may have a water content of greater than or equal to about 5 wt%. The formulation may have a water content of greater than or equal to about 10 wt%. The formulation can have a water content greater than or equal to about 15 wt%. The formulation can have a water content of greater than or equal to about 20 wt%.

The formulation can have a water content of less than or equal to about 30 wt%. The formulation can have a water content of less than or equal to about 25 wt%. The formulation may have a water content of less than or equal to about 20 wt%. The formulation can have a water content of less than or equal to about 15 wt%. The formulation may have a water content of less than or equal to about 10 wt%. The formulation may have a water content of less than or equal to about 8 wt%. The formulation may have a water content of less than or equal to about 5 wt%.

The formulation may have a water content of between about 0.5% and about 30% by weight. The formulation may have a water content of between about 0.5% and about 25% by weight. The formulation may have a water content between about 0.5% and about 20% by weight. The formulation may have a water content of between about 0.5% and about 15% by weight. The formulation may have a water content between about 0.5% and about 10% by weight. The formulation may have a water content of between about 0.5% and about 8% by weight. The formulation may have a water content between about 0.5% and about 5% by weight.

The formulation may have a water content between about 1% and about 20% by weight. The formulation may have a water content between about 5% and about 20% by weight. The formulation may have a water content between about 10% and about 20% by weight. The formulation may have a water content between about 15% and about 20% by weight.

The formulation may comprise nicotine. The formulation may comprise liquid nicotine.

The nicotine may be nicotine base. The nicotine may be a nicotine salt. The formulation may comprise natural nicotine. The formulation may comprise synthetic nicotine.

The nicotine may be provided as a tobacco extract, which may include other tobacco components, such as tobacco flavor components.

The formulation can have a nicotine content of greater than or equal to about 0.5 wt%. The formulation can have a nicotine content greater than or equal to about 1% by weight. The formulation can have a nicotine content greater than or equal to about 1.5 wt%. The formulation can have a nicotine content of greater than or equal to about 2% by weight. The formulation can have a nicotine content of greater than or equal to about 3% by weight. The formulation can have a nicotine content of greater than or equal to about 5% by weight.

The formulation can have a nicotine content of less than or equal to about 10% by weight. The formulation can have a nicotine content of less than or equal to about 8% by weight. The formulation can have a nicotine content of less than or equal to about 5% by weight. The formulation can have a nicotine content of less than or equal to about 3% by weight. The formulation can have a nicotine content of less than or equal to about 2% by weight.

The formulation may have a nicotine content of between about 0.5% and about 10% by weight. For example, the formulation may have a nicotine content of between about 0.5% and about 8% by weight. The formulation may have a nicotine content of between about 0.5% and about 5% by weight. The formulation may have a nicotine content of between about 0.5% and about 3% by weight. The formulation can have a nicotine content between about 1% and about 10% by weight. For example, the formulation may have a nicotine content of between about 1% and about 8% by weight. The formulation may have a nicotine content of between about 1% and about 5% by weight. The formulation may have a nicotine content of between about 1% and about 3% by weight. The formulation can have a nicotine content between about 1% and about 2% by weight. The formulation may have a nicotine content of between about 2% and about 5% by weight. The formulation may have a nicotine content of between about 2% and about 3% by weight. The formulation may have a nicotine content of between about 3% and about 5% by weight.

Preferably, the formulation is a liquid at standard temperature and pressure.

The formulation may comprise one or more organic acids. In some embodiments, the one or more organic acids may be water soluble organic acids. As used herein with reference to the present invention, the term "water-soluble organic acid" describes an organic acid having a water solubility at 20 ℃ of greater than or equal to about 100mg/ml, preferably greater than or equal to about 500mg/ml, more preferably greater than or equal to about 750mg/ml, and most preferably greater than or equal to about 1000 mg/ml.

Unless otherwise indicated, the water solubility values described herein are water solubilities measured based on the following preliminary tests: OECD (1995), Test No.105: Water Solubility, OECD Guidelines for the Testing of Chemicals, section 1, OECD Publishing, Paris, https:// doi.org/10.1787/9789264069589-en. In a stepwise procedure, increasing volumes of distilled water were added to 0.1g of sample (solid matter must be crushed) in a 10ml glass plug cylinder at 20 ℃. However, when the substance is an acid, the sample is added to distilled water in a first step. After each addition of a certain amount of water, the mixture was shaken for 10 minutes and visually inspected for undissolved parts in the sample. If the sample or part thereof has not dissolved after the addition of 10ml of water, the experiment is continued in a 100ml graduated cylinder. Table 1 below gives the approximate solubility in the volume of water in which the sample was completely dissolved.

When the solubility is low, it may take a long time to dissolve the substance, and at least 24 hours should be allowed. If after 24 hours the material has not dissolved, the cylinder is left in the ultrasonic bath at 40 ℃ for 15 minutes and allowed to stand for another 24 hours (up to 96 hours). If the substance is not yet dissolved, the solubility is considered to be below the limit or insoluble.

TABLE 1

The one or more organic acids may be selected from the group consisting of: malonic acid, citric acid, 2-ethylbutyric acid, acetic acid, adipic acid, benzoic acid, butyric acid, cinnamic acid, cycloheptane-carboxylic acid, fumaric acid, glycolic acid, caproic acid, lactic acid, levulinic acid, malic acid, myristic acid, caprylic acid, oxalic acid, propionic acid, pyruvic acid, succinic acid, and undecanoic acid.

In some embodiments, the one or more organic acids are selected from the group consisting of: malonic acid, citric acid, lactic acid, benzoic acid, levulinic acid, fumaric acid and acetic acid.

In some embodiments, the one or more organic acids are selected from the group consisting of: malonic acid, citric acid, lactic acid, fumaric acid and acetic acid.

Most preferably, the one or more organic acids consist of lactic acid.

The formulation can have an organic acid content of greater than or equal to about 0.1 wt%. The formulation can have an organic acid content of greater than or equal to about 0.5 wt%. The formulation can have an organic acid content greater than or equal to about 1% by weight. The formulation can have an organic acid content of greater than or equal to about 2 wt%. The formulation can have an organic acid content of greater than or equal to about 3 wt%. The formulation can have an organic acid content of greater than or equal to about 4 wt%. The formulation can have an organic acid content of greater than or equal to about 5 wt%.

The formulation can have an organic acid content of less than or equal to about 6 wt%. The formulation can have an organic acid content of less than or equal to about 5 wt%. The formulation can have an organic acid content of less than or equal to about 4 wt%. The formulation can have an organic acid content of less than or equal to about 3 wt%. The formulation can have an organic acid content of less than or equal to about 2 wt%. The formulation can have an organic acid content of less than or equal to about 1% by weight. The formulation can have an organic acid content of less than or equal to about 0.5 wt%.

The formulation may have an organic acid content of between about 0.1% and about 6% by weight. The formulation may have an organic acid content of between about 0.1 wt% and about 5 wt%. The formulation may have an organic acid content of between about 0.1 wt% and about 4 wt%. The formulation may have an organic acid content of between about 0.1 wt% and about 3 wt%. The formulation may have an organic acid content of between about 0.1% and about 2% by weight. The formulation may have an organic acid content between about 0.1 wt% and about 1 wt%. The formulation may have an organic acid content between about 0.1 wt% and about 0.5 wt%.

The formulation may have an organic acid content of between about 0.5% and about 6% by weight. The formulation may have an organic acid content of between about 1% and about 6% by weight. The formulation may have an organic acid content of between about 2 wt% and about 6 wt%. The formulation may have an organic acid content of between about 3% and about 6% by weight. The formulation may have an organic acid content of between about 4% and about 6% by weight. The formulation may have an organic acid content of between about 5% and about 6% by weight.

Also provided is a method of forming a formulation as disclosed herein.

The method may include the step of combining the components to form a formulation.

In some embodiments, it may be preferred to combine the components in a particular order, particularly when a number of optional ingredients are included. In the case where one or more metal salts are present, the one or more aerosol-formers may be combined first and the one or more polymeric thickeners added subsequently. Additional optional components may be added at any suitable stage. Optionally, the volatile component natural nicotine can be added as late as possible in the process to reduce losses during processing.

The aerosol-generating system may comprise an aerosol-generating article.

The aerosol-generating article may comprise a nebulizer configured to generate an aerosol from the formulation.

The aerosol-generating article may comprise a cartridge.

The cartridge containing the formulation and the nebulizer may be referred to as a "cartomiser" (cartomiser).

The atomiser may be a thermal atomiser.

As used herein, the term "thermal atomizer" describes an atomizer configured to heat a formulation to generate an aerosol.

The aerosol-generating article may comprise any suitable type of thermal atomiser. For example, the thermal atomizer may comprise a heater. The thermal atomizer may comprise an electric heater. In one example, the thermal atomizer may comprise an electric heater comprising a resistive heating element. In another example, the thermal atomizer may comprise an electric heater comprising an induction heating element.

The heater may comprise a heating element. The heating element may be a grid element. The heating element may be a mesh layer. The heating element may be a mesh element. The heating element may be a mesh layer. In these embodiments, the formulation may flow into interstitial spaces that form a mesh or network.

The aerosol-generating article may comprise a mixer. The mixer may be adapted to mix at least two liquids. The mixer is operable to agitate the formulation in response to user input. In one example, the mixer may be mechanically operated. In another example, the mixer may be electrically operated. The mixer may be a stirrer. The agitator may be a linear resonant actuator. The mixer may be a different type of device or mechanism suitable for mixing liquids, such as a magnetic stirrer.

Advantageously, the inclusion of the mixer prevents the particles of the polymeric thickener from settling out of solution, thereby providing a better seal.

The aerosol-generating system may comprise an aerosol-generating device.

The aerosol-generating device may comprise a reservoir for containing the formulation.

The aerosol-generating device may comprise a housing defining a device cavity configured to receive at least a portion of an aerosol-generating article.

The aerosol-generating device may comprise a nebulizer configured to generate an aerosol from the formulation.

The atomiser may be a thermal atomiser.

The aerosol-generating device may comprise any suitable type of thermal atomiser. For example, the thermal atomizer may comprise a heater. The thermal atomizer may comprise an electric heater. In one example, the thermal atomizer may comprise an electric heater comprising a resistive heating element. In another example, the thermal atomizer may comprise an electric heater comprising an induction heating element.

The aerosol-generating device may comprise a mixer. The mixer may be adapted to mix at least two liquids. The mixer is operable to agitate the formulation in response to user input. In one example, the mixer may be mechanically operated. In another example, the mixer may be electrically operated. The mixer may be a stirrer. The agitator may be a linear resonant actuator. The mixer may be a different type of device or mechanism suitable for mixing liquids, such as a magnetic stirrer.

According to the present invention there is also provided an aerosol-generating system comprising a formulation according to the present invention and a nebuliser configured to generate an aerosol from the formulation.

The atomiser may be a thermal atomiser.

The aerosol-generating system may comprise any suitable type of thermal atomiser.

The thermal atomizer may comprise an electric heater. For example, the thermal atomizer may comprise an electric heater comprising a heating element, which may comprise a resistive heating element or an inductive heating element.

The heating element may be a mesh or mesh element or layer. In these embodiments, the formulation may flow into the interstitial spaces forming the mesh or net-like elements.

An aerosol-generating system may comprise an aerosol-generating article comprising a formulation according to the invention and an aerosol-generating device comprising a housing defining a device cavity configured to receive at least a portion of the aerosol-generating article.

An aerosol-generating system may comprise a consumable aerosol-generating article comprising a formulation according to the invention and a reusable aerosol-generating device comprising a housing defining a device cavity configured to receive at least a portion of the aerosol-generating article.

The aerosol-generating device may comprise a battery and control electronics.

The aerosol-generating system may comprise: an aerosol-generating article according to the invention comprising a formulation and a nebuliser; and an aerosol-generating device comprising a housing defining a device cavity configured to receive at least a portion of an aerosol-generating article.

The aerosol-generating system may comprise: an aerosol-generating article comprising a formulation according to the invention; and an aerosol-generating device comprising a housing defining a device cavity configured to receive at least a portion of an aerosol-generating article; and an atomizer.

For the avoidance of doubt, the above features relating to the formulation may also relate to the aerosol-generating article, the aerosol-generating device and the aerosol-generating system, where appropriate. Similarly, features described above in relation to the aerosol-generating article may also relate to the aerosol-generating device and the aerosol-generating system, and vice versa, where appropriate.

Drawings

Specific embodiments will now be described, by way of example only, with reference to the following examples and the accompanying drawings, in which:

figure 1 schematically shows a cross-sectional side view of an aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article comprising a formulation according to the invention;

figure 2 schematically shows a cross-sectional view of the aerosol-generating system of figure 1, wherein the aerosol-generating article is inserted into an aerosol-generating device;

figure 3 schematically shows a cross-sectional view of an alternative aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article comprising a formulation according to the invention;

figure 4 schematically shows a cross-sectional view of an aerosol-generating article comprising a formulation according to the present invention;

figure 5 schematically shows a cross-sectional view of an aerosol-generating article comprising a formulation according to the present invention;

figure 6 is a graph showing the average aerosolized collection mass (in milligrams per puff) for a series of different aerosol-former compositions;

figure 7 is a graph showing the average nicotine (in mg/puff) for a range of different aerosol-former compositions; and

figure 8 is a graph showing the average nicotine percentage for a range of different aerosol former compositions.

Detailed Description

Aerosol-generating systems for delivery to a user typically include a nebulizer configured to generate an inhalable aerosol from a formulation. Some known aerosol-generating systems include a thermal atomizer (such as an electric heater) configured to heat and vaporize a formulation to produce an aerosol. A typical formulation for an aerosol-generating system is a nicotine formulation, which may be a liquid nicotine formulation comprising an aerosol former such as glycerol and/or propylene glycol.

An aerosol-generating system may comprise an aerosol-generating device and an aerosol-generating article containing a formulation. Typical aerosol-generating systems may suffer from undesirable leakage of the formulation from the aerosol-generating article. Leakage of the formulation can occur in many different situations, such as: when there is too much formulation in the reservoir of the aerosol-generating article; when the material forming one or more parts of the aerosol-generating article or system fails to retain the designed formulation; due to pressure variations, for example at high altitude during aircraft transportation; or at high temperatures, for example due to hot weather.

In contrast to typical formulations, it is desirable to provide a formulation that: which reduces the risk of leakage from the aerosol-generating article or system.

Fig. 1 and 2 show an aerosol-generating system comprising an aerosol-generating device 10 and an aerosol-generating article 20. In this example, the aerosol-generating article 20 is a cartridge.

The aerosol-generating device 10 is configured to receive an aerosol-generating article 20 in the cavity 18. The aerosol-generating article 20 comprises a housing 24. The housing 24 defines the reservoir 22. The reservoir 22 has a reservoir opening that can be covered by a removable cap 26. An aerosol-forming substrate is disposed in the reservoir 22. The aerosol-forming substrate in the reservoir 22 may be a formulation according to the invention.

In the example shown in fig. 1 and 2, the aerosol-generating article 20 comprises an atomizer configured to generate an aerosol from the formulation in the reservoir 22. The atomiser may be a thermal atomiser. In the example shown in fig. 1 and 2, the atomizer is an electric heater 30.

In the example of fig. 1 and 2, the aerosol-generating article 20 contains an aerosol-forming substrate and an atomizer, and may therefore be referred to as a "cartomizer".

When the aerosol-forming substrate provided in the reservoir 22 is exhausted, the user may replace the aerosol-generating article 20.

Figure 1 shows an aerosol-generating article 20 prior to insertion into an aerosol-generating device 10. The arrow 1 in fig. 1 indicates the direction of insertion of the aerosol-generating article 20 into the aerosol-generating device 10.

The aerosol-generating device 10 is portable and has a size comparable to a conventional cigar or cigarette. The aerosol-generating device 10 comprises a body 11 and a mouthpiece portion 12. The body 11 contains a battery 14 (such as a lithium iron phosphate battery), control electronics 16 and a cavity 18.

The mouthpiece portion 12 is connected to the body 11 by a hinged connection 21 and is movable between an open position as shown in figure 1 and a closed position as shown in figure 2. The mouthpiece portion 12 is placed in an open position to allow insertion and removal of the aerosol-generating article 20, and in a closed position when the aerosol-generating system is to be used to generate an aerosol.

The mouthpiece portion 12 comprises a plurality of air inlets 13 and outlets 15. In use, the user sucks or sucks on the outlet 15 to draw air from the air inlet 13, through the mouthpiece portion to the outlet 15 and then into the mouth or lungs of the user. An internal baffle 17 is provided to force air flowing through the mouthpiece portion 12 through the aerosol-generating article 20.

The housing 24 comprises a capillary material soaked in an aerosol-forming substrate. The capillary tubing material in this example is positioned adjacent to the electric heater 30.

The cavity 18 has a circular cross-section and is sized to receive a housing 24 of the aerosol-generating article 20. Electrical connectors 19 are provided at the sides of the cavity 18 to provide electrical connections between the control electronics 16 and the battery 14 and corresponding electrical contacts on the aerosol-generating article 20. This arrangement allows power to be supplied to the electric heater 30.

Figure 2 shows an aerosol-generating article 20 inserted into the cavity 18 of the aerosol-generating device 10. In this position, the electrical connectors 19 rest on corresponding electrical contacts on the aerosol-generating article 20. The lid 26 has been completely removed and the mouthpiece portion 12 has been moved to the closed position.

The mouthpiece portion 12 is held in the closed position by a clasping mechanism (not shown). It will be apparent to those skilled in the art that other suitable mechanisms for retaining the mouthpiece in the closed position may be used, such as a snap fit or magnetic snap open.

The mouthpiece portion 12 in the closed position holds the aerosol-generating article 20 in electrical contact with the electrical connector 19 so that a good electrical connection is maintained in use regardless of the orientation of the aerosol-generating system.

In use, when the aerosol-generating device 10 is actuated by a user, the electric heater 30 aerosolizes at least a portion of the aerosol-forming substrate in the reservoir 22. When the user sucks or sucks on the outlet 15, air flows through the air inlet 13 and through the electric heater 30 and capillary material. Air flowing through the electric heater 30 and the capillary material entrains the volatilized aerosol components from the evaporated aerosol-forming substrate. The air with entrained aerosol-forming substrate then flows out through the outlet 15 and towards the user. This gas flow pattern is shown in figure 2.

Figure 3 shows another embodiment of an aerosol-generating system. The embodiment shown in fig. 3 works in much the same way as the embodiment shown in fig. 1 and 2. However, in the embodiment of fig. 3, the aerosol-generating article 20 is not removable from the aerosol-generating device 10. Conversely, after the reservoir 22 has been depleted of aerosol-generating substrate, a user may refill the reservoir 22 through the reservoir opening 40.

In fig. 3, the reservoir opening 40 is shown in an open position, wherein it may be refilled with an aerosol generating substrate. However, the reservoir opening 40 may be sealed with a closure, such as a lid (not shown).

In addition, the embodiment shown in fig. 3 operates in a similar manner to the embodiment shown in fig. 1 and 2.

Figures 4 and 5 are schematic cross-sectional views of an alternative aerosol-generating article 200. Figure 4 shows the aerosol-generating article 200 prior to use by a user. The aerosol-generating article 200 includes a body 212 defining a reservoir 210 having a reservoir opening 215. An aerosol-forming substrate 211 is disposed in the reservoir 210. The aerosol-generating article 200 includes a heater 222 positioned across the reservoir opening 215. In this example, the heater 222 has a heating element in the form of a mesh layer 223. The aerosol-generating article 200 further comprises a transfer element 224. The transfer member 224 is preferably formed of a porous material. In the example of fig. 4, the transfer element 224 is formed from a layer of fiberglass. The transfer element 224 controls the flow of the aerosol-forming substrate 211 from the reservoir 210 to the mesh layer 213 of the heater 222. In this example, the aerosol-forming substrate 211 is a formulation according to the invention.

In use, the formulation flows from the reservoir 210 into the porous transfer element 224. The formulation then flows to the mesh layer 223 of the heater 222 where it is thermally gasified into an aerosol.

It may be advantageous to mix the aerosol-forming substrate 211 before or during heating of the aerosol-forming substrate 211 by the heater 222. Mixing the aerosol-forming substrate 211 ensures that the aerosol-forming substrate 211 becomes or remains a substantially homogeneous mixture. In the example shown in fig. 4, the aerosol-generating article 200 comprises a mixer operable to agitate the aerosol-forming substrate 211. The mixer may be mechanically or electrically operated. In this example, the mixer is an agitator 226. The agitator 226 may be a linear resonant actuator. In other examples, the mixer may be a different type of device or mechanism suitable for mixing liquids, such as a magnetic stirrer. In another example, the aerosol-forming substrate 211 may be mechanically mixed by a user. In another example, the aerosol-forming substrate 211 may be mixed during the manufacturing process, for example by ultrasonic vibration.

Examples

Three formulations according to the invention (examples A, B and C) having the compositions shown in Table 1 were prepared. The formulations of examples A, B and C were liquids at standard temperature and pressure.

TABLE 2

Formulations A, B and C are prepared by mixing the components together, for example, in a container. An aerosol former, which in these examples is glycerol, is first added to the container. Next, a metal salt, which in these examples is sodium stearate, is added to the container. Water is then added to the vessel. Finally, a polymeric thickener (in this case polyvinyl alcohol) is added to the vessel. The components are then mixed together in a container.

The formulations of examples a and B were then heated on a hot plate for a period of time. In this example, the formulations of examples a and B were heated for six minutes. Samples of the formulations of examples a and B were heated to different temperatures. In one example, samples of the formulations of examples a and B were heated to 200 degrees celsius. In another embodiment, the formulations of examples a and B are heated to 120 degrees celsius. In another embodiment, the formulations of examples a and B are heated to 90 degrees celsius. The formulations of examples a and B were then removed from the hot plate.

After cooling, some of the six samples solidified. Both examples a and B, heated to 200 degrees celsius, were cured. Examples a and B, heated to 120 degrees celsius, were also both cured. Example a heated to 90 degrees celsius did not cure and remained liquid. However, example B heated to 90 degrees did cure.

An example of using a formulation according to the invention as an aerosol-forming substrate will now be described with reference to the formulation of example C when used as an aerosol-forming substrate 211 in the aerosol-generating article 200 shown in figures 4 and 5.

Advantageously, as an initial step, the agitator 226 may be activated for a period of time to mix the aerosol-forming substrate. In another embodiment, the aerosol-generating article 200 may be shaken by a user in order to mix the aerosol-forming substrate 211. The initial step of mixing ensures that the aerosol-forming substrate 211 is a substantially homogeneous mixture prior to heating.

The aerosol-generating article 200 is then inserted into the aerosol-generating device 10 shown in figure 1.

The user then activates the aerosol-generating device. Activation of the aerosol-generating device involves activation of the heater 222 of the aerosol-generating article 200. Activation of the heater 222 causes a portion of the aerosol-generating substrate 211 contained within the transfer element 224 to be heated. Heating of the aerosol-forming substrate 211 contained within the transfer element 224 causes at least a portion of the aerosol-generating substrate 211 to vaporize into an aerosol. In this embodiment, heater 222 is activated at 0.8 watts for a period of six minutes. In one embodiment, the heater 222 may be activated at different power levels. In another embodiment, the heater 222 may be activated for different periods of time.

Activating the heater 222 at 0.8 watts for six minutes increases the temperature of the mesh layer 223 to approximately 200 degrees celsius.

As the mesh layer 223 of the heater 222 cools, the heated but unevaporated aerosol-forming substrate 211 solidifies into the solid layer 225. The solid layer 225 may be retained within the transfer element 224. In this embodiment, the formed solid layer 225 completely covers the reservoir opening 215.

Figure 5 shows the aerosol-generating article 200 after first use by a user. That is, fig. 5 shows the aerosol-generating article 200 after a first heating cycle of six minutes has occurred.

As can be seen from fig. 5, after the aerosol-generating article 200 has been used for the first time, a solid layer 225 has been partially formed within the transfer element 224. The solid layer 225 is also in contact with the mesh layer 223 of the heater 222. In the embodiment shown in fig. 5, the solid layer 225 internally seals the reservoir opening 215. Advantageously, sealing the reservoir opening 215 may prevent the formulation (i.e., aerosol-forming substrate) from escaping from the reservoir 210.

The aerosol-generating article 200 may be used several times before the aerosol-generating substrate 211 contained in the reservoir 210 is completely consumed. Accordingly, the aerosol-generating article 200 may undergo multiple heating cycles.

Prior to the second heating cycle, the solid layer 225 remains in position to block the porous mesh layer 223 (as shown in fig. 5) and prevents the formulation from escaping from the reservoir opening 215. When the aerosol-generating article 200 is used a second time, the heater 222 is activated for a second heating cycle. The heater 222 is activated to perform a second heating cycle 222 to heat the mesh layer 223. Heating the mesh layer 223 increases the temperature of the solid layer 225 formed on the mesh layer 223 until the solid layer 225 melts into a liquid. At this point, in some embodiments, the aerosol-forming substrate may be a complete liquid. As the temperature of the aerosol-forming substrate 211 increases, a portion of the aerosol-forming substrate 211 is evaporated by the heater 222.

After the second heating cycle is complete, the heated but unevaporated aerosol-forming substrate 211 solidifies into another solid layer 225 within the transfer member 224 as the mesh layer 223 of the heater 222 cools. In this embodiment, the solid layer 225 again covers the mesh layer 223 and thus again seals the reservoir opening 215, preventing the aerosol-forming substrate 211 from leaking out of the reservoir 210.

In an alternative embodiment, the first heating cycle is initiated during manufacturing. For example, a first heating cycle may be initiated after the reservoir 210 has been filled with the aerosol-forming substrate 211.

In one embodiment, another step is performed. This further step is optional and is not necessary to provide the advantages and effects of the invention. After the heating cycle has been initiated and the solid layer 225 begins to form as the aerosol-forming substrate 211 cools, the aerosol-generating article 200 is rotated into a particular orientation that facilitates the formation of the solid layer 225 at the location of the barrier web layer 223, thereby sealing the closed reservoir opening 215. For example, the aerosol-generating article 200 may be stored upside down after the first heating cycle.

Advantageously, the solid layer 225 formed after the coolant cools provides a barrier that seals the closed reservoir opening 215. Sealing the reservoir 215 prevents fluid from escaping from the reservoir 215. Thus, the solid layer 225 prevents the formulation from leaking from the reservoir 215 between uses of the aerosol-generating device 600. Reservoir seals may be advantageous in certain situations, which typically result in leakage of the formulation from the reservoir 215, such as due to pressure changes (e.g., when a user is climbing a hill or traveling by airplane) and at high temperatures (e.g., due to hot summer months).

Figure 6 shows the average aerosolized collection mass (in milligrams per puff) for a range of different aerosol former compositions as the weight percent of Propylene Glycol (PG) was varied relative to the weight percent of Vegetable Glycerin (VG). For example, the data for "25% PGvsVG" is for a formulation comprising an aerosol former composition containing 25% by weight propylene glycol and 75% by weight vegetable glycerin.

Figure 7 is a graph showing the average nicotine (in milligrams per puff) for a range of different aerosol former compositions as the weight percent of Propylene Glycol (PG) is varied relative to the weight percent of Vegetable Glycerin (VG). For example, the data for "25% PGvsVG" is for a formulation comprising an aerosol former composition containing 25% by weight propylene glycol and 75% by weight vegetable glycerin.

Fig. 8 is a graph showing the average nicotine percentage for a range of different aerosol former compositions as the weight percentage of Propylene Glycol (PG) was varied relative to the weight percentage of Vegetable Glycerin (VG). For example, the data for "25% PGvsVG" is for a formulation comprising an aerosol former composition containing 25% by weight propylene glycol and 75% by weight vegetable glycerin.

The data in the figures indicate that the nicotine content of the aerosol is improved by incorporating propylene glycol as the aerosol former in a nicotine-containing formulation, as discussed above. For example, the weight percentage of nicotine is highest with 5% by weight propylene glycol in the aerosol former. This improvement may be due to the higher evaporation efficiency of nicotine, since propylene glycol has a lower boiling point (188 ℃) compared to glycerol (290 ℃).

However, if there is a significant amount of propylene glycol in the formulation (e.g., 25% by weight propylene glycol), the nicotine content of the aerosol will be reduced because the propylene glycol can evaporate during the heating cycle. Therefore, it is advantageous to have a limited amount of propylene glycol in the nicotine formulation.

The exemplary embodiments described above are not intended to limit the scope of the claims. Other embodiments consistent with the above exemplary embodiments will be apparent to those skilled in the art. Features described with respect to one embodiment may also be applicable to other embodiments.

Claims

1. A formulation for an aerosol-generating system, the formulation comprising:

one or more aerosol forming agents;

one or more metal salts; and

one or more polymeric thickeners, wherein the polymeric thickener,

wherein the formulation has a polymeric thickener content of greater than or equal to about 0.5 wt%,

wherein the one or more metal salts comprise one or more metal stearates.

2. The formulation of claim 1, wherein the formulation has a polymeric thickener content of between about 5% and about 20% by weight.

3. The formulation according to any one of the preceding claims, wherein the one or more polymeric thickeners are selected from the group consisting of: polyvinyl alcohol, polyethylene glycol, polypropylene glycol and starch.

4. The formulation of any one of the preceding claims, wherein the one or more metal salts are selected from the group consisting of: metal alginates, metal benzoates, metal cinnamates, metal cycloheptane carboxylates, metal levulinates, metal propionates, metal stearates, and metal undecanoates, preferably the one or more metal salts are selected from the group consisting of: metal cinnamates, metal cycloheptane carboxylates, metal stearates, and metal undecanoates.

5. The formulation of any one of the preceding claims, wherein the formulation has a metal stearate content of greater than or equal to about 0.5%.

6. The formulation of any one of the preceding claims, wherein the one or more metal stearates comprise sodium stearate.

7. A formulation according to any preceding claim, wherein the one or more aerosol-former comprises glycerol.

8. The formulation of claim 7, wherein the one or more aerosol-forming agents comprise glycerin and propylene glycol.

9. The formulation of claim 8, wherein the ratio of weight percent of glycerin content to weight percent of propylene glycol content in the formulation is greater than or equal to about 1.5.

10. The formulation of any one of the preceding claims, wherein the formulation has an aerosol former content of greater than or equal to about 50 wt%.

11. The formulation of any one of the preceding claims, comprising water.

12. The formulation of claim 11, having a water content of less than or equal to about 30% by weight.

13. An aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a formulation according to any one of claims 1 to 14.

14. An aerosol-generating system, the aerosol-generating system comprising:

the formulation of any one of claims 1 to 14; and

a nebulizer configured to generate an aerosol from the formulation.